Use of synthetic oxytocin (sOT) for labor and postpartum management has escalated. Estimates now range around 50% of labors, with a particular increase in elective induction of labor (lOL) and nearly 100% postpartum use. Meanwhile neuroscience research has examined the role of OT as it relates to a range of normal behaviors (bonding, social interaction, lactation) and pathological conditions (depression, anxiety, cardiovascular disease, autism). Clinical studies, however, have focused mostly on dosing strategies and immediate effects of OT on mother or infant. The use of sOT has been tied to a number of adverse outcomes: increased pain management, fetal distress, and surgical birth. sOT use in labor is now listed on the Institute for Safe Medication Practices list as a "high alert medicine". Despite these compelling reasons to investigate the consequences of sOT, the neurobiological and endocrine effects of OT have not yet been fully explored, especially in the context of parturition. The few studies examining longer-lasting effects of sOT show an association with breastfeeding problems and changes in maternal endogenous (eOT)/prolactin expression in the first few days after birth. The goal of this application therefore is to develop a new translational, animal paradigm that will mimic human birth practices allowing us to examine the dose-dependent effects of sOT on maternal behavior, neuroendocrinology and physiology. A small rodent, Microtus ochrogaster (prairie vole), serves as a unique model for studying peptides and behavior. This species shares with humans high levels of sociality, pair bond formation, and biparental care. Prairie voles also have levels of eOT in the range of humans (unlike rats and mice). Several effects of eOT in adulthood and developmental consequences of OT in infants are known in this species. Specific aims here include the analysis of the dose-dependent effects of sOT exposure during birth on 1) subsequent maternal behavior, and indices of anxiety, and depression, 2) subsequent central and plasma peptides and components of the HPA axis, using immunohistochemistry and enzyme-linked immunoassay, and 3) OT receptor gene expression in target maternal organs: brain (region specific), mammary tissue, uterus, and heart via reverse transcriptase polymerase chain reaction (rt-PCR). As the use of Pitocin(R) continues to climb in obstetric practice, the consequences of the drug need to be understood. The potential for an extended effect is reasonable given findings in animal research and limited human data. Public health interest in this study lies in minimizing risks during birth. At this time, science cannot say with certainty that induction or augmentation of labor carries no long-term effects.